•••••••Trading•••••••
Explicit costs
commissions, taxes, stamp duties, and fees.
•••••••Trading•••••••
Implicit costs
bid-ask spread, market or price impact costs, opportunity costs, and delay costs (a.k.a. slippage costs).
•••••••Trading•••••••
VWAP Implicit cost
Implicit cost = # shares * (Executed price – VWAP)
•••••••Trading•••••••
Algorithmic Trading
Algorithmic Trading - execute orders with minimal risk and costs.
•••••••Trading•••••••
Implementation Shortfall (IS)
CD-ROM
Straightforward approach:

•••••••Trading•••••••
Effective spread
Effective spread = 2 × (Actual execution price − Mid-point of market quote at time of order entry)
Quoted spread = ask - bid
Mid-point = (ask + bid) / 2